The Thoracic cavity will be another major influence towards postural balance.  This area of the spinal musculature will be the fulcrum of where the upper body will maintain its structural integrity.  It will also act as an aid to help the transverse abdominis reintroduce itself into functionality.  The thoracic region will usually be in dysfunction as a result of a poor lumbopelvic function.  When the hip flexors get into a shortened state, they will then shunt the gluteal systems from being able to use hip extension during functional movement.  

This will then trigger a reaction from the lumbar erector spinae that will eventually create an anterior shift in the pelvis. As the pelvis is moved into a forward position, the T-spine will react in a flexed position to compensate and find structural balance. If we analyze the abdominal musculature, we will see that the excessive flexing forward of the thoracic spine will undoubtedly wire in tension into the upper abdominal region.  

Once the upper abdominal region has been completely wired into a path of dysfunction, the thoracic spine will no longer be able to go into extension.  The lumbar will now take over in this extension cycle to compensate.  Repeat this cycle for years at a time and a new associative response system will become wired in neurologically.  By developing the musculature that acts in the thoracic region, we will elongate the muscular structures in the upper abdominals.  

This will then allow the TVA to get into a functional length-tension relationship, stabilizing the lumbar spine and foundationally re-introduce itself as the dominant structure for core stability.  The difficulty in accomplishing this task will be found in maintaining a neutral spine while extending the thoracic region.  Since the imbalance of lumbar anterior shifting has been ingrained for so long, it is going to be quite the challenge for the brain to make new associations upon what functional extension in the thoracic should feel like.  The tension in the will be the guiding force for you to understand whether you are making the associations necessary to correct these imbalances or not.